Printers such as ink-jet printers employ printing elements which require periodic removal and replacement. In the case of inkjet printers, the printing elements include nozzle arrays typically mounted on pens or print cartridges, and can require periodic replacement as the nozzle array wears out, becomes clogged, or when an internal ink supply becomes exhausted.
In the past, the user has manually inserted and removed the inkjet pens or print cartridges on the printer. As users are allowed to independently insert and remove the inkjet pens and print cartridges, a number of challenges have become manifest. Challenges facing designers of inkjet printers include difficulty in guiding the inkjet pens into an associated carriage, confusion about the color of pen to be installed in each carriage, and the proper orientation of the pen when being inserted into the carriage.
Traditionally, frontward insertion was not smooth with many inkjet carriage designs. Often, the inkjet pen would hit a hard stop before having to be wiggled into position. Traditional printers attempted to the frontward insertion of the inkjet pens with illustrations contained with the pen and the printer lid aimed at preventing incorrect insertion.
Similarly, solutions aimed at preventing inappropriate or forced color swapping were traditionally limited to the inclusion of illustrative features on the pen lid. While illustrations are helpful to some users, the inkjet pen could still be inserted deep into a wrong cavity of the carriage, and in some cases the inkjet pen could be pushed to the point of getting stuck, resulting in the need to replace these printers. Additionally, inappropriate color swapping could cause damage to the carriage latch mechanism due to varying pen design.
Backwards insertion also causes dissatisfaction to customers and potential damage to printers. Similar to the previous situations, traditional methods for preventing incorrect insertion included modifying features on the pen lid to further inform the user of correct pen insertion. However, this did not in any way prevent the pen from being incorrectly plugged deep into the cavity where potentially expensive damage could result.